1. Field of the Invention
This invention relates to a plasma display apparatus.
2. Description of the Related Art
For example, a plasma display panel (designated as PDP hereinafter) is known as a plane display apparatus of a dotted matrix type. In many cases, the PDP is used as a display of a personal computer, a word processor, or the like. Since the PDP can perform a high speed display and can easily provide a large screen, PDP is expected as larger sized flat type display means having the size of 20 inches or more.
FIG. 1 shows a surface discharge type PDP comprising a 3-electrode structure of an AC driving type in a unit cell. This PDP comprises: a pair of parallel disposed glass substrates 301 and 302 spaced through a discharge space 308; a plurality of paired, parallel sustaining electrodes (maintaining electrodes) X and Y formed on an inner surface of the glass substrate 301 forming a display surface; a dielectric layer 306 covering the sustain electrodes X and Y; and a protecting layer 307 made of MgO and covering the dielectric layer 306. Each of the sustain electrodes X and Y is made up of a belt-shaped wider transparent electrode 303 and a bus electrode 304 of a metal film overlapped for compensating a conductivity of the sustain electrode.
The PDP further comprises: barrier ribs 310 formed on an inner surface of the glass substrate 302 and extending perpendicularly to the sustain electrodes X and Y, the barrier ribs dividing the discharge space 308 to unit light emitting regions; a column electrode 305 formed between the barrier ribs 310 on the glass substrate and extending perpendicularly to the sustain electrodes X and Y; and a plurality of fluorescent layers 309 for emitting predetermined colored light. The discharge space 308 is filled with a discharge gas including neon and a smaller quantity of xenon.
In the operation of the above PDP, a driving voltage exceeding a discharge starting voltage is applied between the sustain electrodes X and Y. As a result, a surface discharge is caused near a surface of the dielectric layer 306, predetermined amount of wall charges are then accumulated in the surface of the dielectric layer 306, and the discharge is ceased.
A surface discharge is caused each tine a sustaining pulse having an opposite polarity to that of the wall charges is alternately applied to the sustain electrodes X and Y. Ultraviolet rays generated by the application of the pulses excite the fluorescent layer 309 to emits a light therefrom.
FIG. 2 shows a block diagram illustrating a driving apparatus of a conventional plasma display panel. In FIG. 2, a video signal processor 101 receives a composite video signal to extract R, G, and B video signals corresponding to red, green, and blue video components therefrom to supply the extracted video signals to A/D convertors 104R, 104G, and 104B. A synchronous separator 102 extracts horizontal and vertical synchronous signals from the composite video signal, thereby supplying them to a row electrode driver 108. Signal processors 105R, 105G, and 105B process signal outputs from the corresponding A/D convertors 104R, 104G, and 104B in the manner that the signal outputs can be stored in the corresponding frame memories 106R, 106G, and 106B. Then, the processed signal outputs are stored in the corresponding frame memories 106R, 106G, and 106B. The signals stored in the frame memories 106R, 106G, and 106B are sequentially read out and mixed in a mixture processor 107. The mixed signals from the mixture processor 107 are supplied to a column electrode driver 409 in the order of red, green, and blue, thereby driving the corresponding column electrodes D.sub.1 -D.sub.3n.
The synchronous separator 102 supplies its output signal to a row electrode driver 108 at a proper timing through a controller 103 to drive row electrodes X.sub.1 -X.sub.m, and Y.sub.1 -Y.sub.m.
When the row electrode driver 108 applies a scanning pulse to a PDP 110, the PDP 110 starts discharge light emissions in accordance with pixel data pulses, and then maintains the light emitting state during a period in which the application of sustain pulses to the PDP 110 is continued. when the row electrode driver 108 applies erasing pulses to the PDP 110, the discharge light emissions are ceased. Thus, the driving pulses for the row electrode consist of the scanning pulses, the sustain pulses, and the erasing pulse.
FIG. 3 shows a detailed diagram of the column electrode driver. In FIG. 3, 64-bit shift registers 501.sub.1 -501.sub.3n receive the data consisting of red, green, and blue and subjected to the mixing processes, and then convert the received data in series into parallel ones. Latches 502.sub.1 -502.sub.n latch the outputs of the 64-bit shift registers 501.sub.1 -501.sub.3n. Outputs of the latches control column electrodes D.sub.1 -D.sub.m.
In the conventional colored PDP, in order to drive each cell of red, green, and blue in one pixel, a problem arises that the mixing processes of three primary color data are necessary before the column electrode driver receives them. In addition, since a shift register generally includes a plurality of bits consisting of binary codes, and one data corresponding to three bits of red, green, and blue is distributed over an adjacent shift register, a further problem arises that its processing is required.